From 06e912dbe21d5dcf6554f7ed1ef97abb25711c57 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 20 Nov 2017 22:55:10 +0300
Subject: [PATCH] Search for bundles in badly formatted streams

---
 doc/bundles.texi                              |  4 +-
 .../nncp/cmd/nncp-bundle/main.go              | 40 +++++++++++++------
 src/cypherpunks.ru/nncp/pkt.go                |  2 +
 3 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/doc/bundles.texi b/doc/bundles.texi
index 9b2f8fc..bb965b2 100644
--- a/doc/bundles.texi
+++ b/doc/bundles.texi
@@ -51,5 +51,5 @@ can contain mix of various recipients.
 Technically bundle is valid POSIX.1
 @url{http://www.freebsd.org/cgi/man.cgi?query=tar&sektion=5, tar archive},
 with directory/files hierarchy identical to that is used in
-@ref{nncp-xfer}. So bundle can also be created by manual tar-ing of
-@command{nncp-xfer} resulting directory.
+@ref{nncp-xfer}: @file{NNCP/RECIPIENT/SENDER/PACKET}. So bundle can also
+be created by manual tar-ing of @command{nncp-xfer} resulting directory.
diff --git a/src/cypherpunks.ru/nncp/cmd/nncp-bundle/main.go b/src/cypherpunks.ru/nncp/cmd/nncp-bundle/main.go
index 210a140..1068251 100644
--- a/src/cypherpunks.ru/nncp/cmd/nncp-bundle/main.go
+++ b/src/cypherpunks.ru/nncp/cmd/nncp-bundle/main.go
@@ -124,6 +124,7 @@ func main() {
 				}
 				if err = tarWr.WriteHeader(&tar.Header{
 					Name: strings.Join([]string{
+						nncp.NNCPBundlePrefix,
 						nodeId.String(),
 						ctx.SelfId.String(),
 						pktName,
@@ -158,9 +159,11 @@ func main() {
 			log.Fatalln("Error during tar closing:", err)
 		}
 	} else {
-		tarR := tar.NewReader(bufio.NewReaderSize(os.Stdin, CopyBufSize))
+		bufStdin := bufio.NewReaderSize(os.Stdin, CopyBufSize*2)
+		var peeked []byte
+		var prefixIdx int
+		var tarR *tar.Reader
 		var entry *tar.Header
-		var sepIndex int
 		var exists bool
 		pktEncBuf := make([]byte, nncp.PktEncOverhead)
 		var pktEnc *nncp.PktEnc
@@ -168,25 +171,38 @@ func main() {
 		var selfPath string
 		var dstPath string
 		for {
+			peeked, err = bufStdin.Peek(CopyBufSize)
+			if err != nil && err != io.EOF {
+				log.Fatalln("Error during reading:", err)
+			}
+			prefixIdx = bytes.Index(peeked, []byte(nncp.NNCPBundlePrefix))
+			if prefixIdx == -1 {
+				if err == io.EOF {
+					break
+				}
+				bufStdin.Discard(bufStdin.Buffered() - (len(nncp.NNCPBundlePrefix) - 1))
+				continue
+			}
+			bufStdin.Discard(prefixIdx)
+			tarR = tar.NewReader(bufStdin)
 			sds["xx"] = string(nncp.TRx)
 			entry, err = tarR.Next()
 			if err != nil {
-				if err == io.EOF {
-					break
+				if err != io.EOF {
+					ctx.LogD(
+						"nncp-bundle",
+						nncp.SdsAdd(sds, nncp.SDS{"err": err}),
+						"error reading tar",
+					)
 				}
-				log.Fatalln("Error during tar reading:", err)
+				continue
 			}
 			sds["pkt"] = entry.Name
 			if entry.Size < nncp.PktEncOverhead {
 				ctx.LogD("nncp-bundle", sds, "Too small packet")
 				continue
 			}
-			sepIndex = strings.LastIndex(entry.Name, "/")
-			if sepIndex == -1 {
-				ctx.LogD("nncp-bundle", sds, "Bad packet name")
-				continue
-			}
-			pktName = entry.Name[sepIndex+1:]
+			pktName = filepath.Base(entry.Name)
 			if _, err = nncp.FromBase32(pktName); err != nil {
 				ctx.LogD("nncp-bundle", sds, "Bad packet name")
 				continue
@@ -195,7 +211,7 @@ func main() {
 				ctx.LogD("nncp-bundle", nncp.SdsAdd(sds, nncp.SDS{"err": err}), "read")
 				continue
 			}
-			if _, err = xdr.Unmarshal(bytes.NewBuffer(pktEncBuf), &pktEnc); err != nil {
+			if _, err = xdr.Unmarshal(bytes.NewReader(pktEncBuf), &pktEnc); err != nil {
 				ctx.LogD("nncp-bundle", sds, "Bad packet structure")
 				continue
 			}
diff --git a/src/cypherpunks.ru/nncp/pkt.go b/src/cypherpunks.ru/nncp/pkt.go
index fa46282..1af1816 100644
--- a/src/cypherpunks.ru/nncp/pkt.go
+++ b/src/cypherpunks.ru/nncp/pkt.go
@@ -49,6 +49,8 @@ const (
 	DefaultNiceMail = 64
 	DefaultNiceFreq = 64
 	DefaultNiceFile = 196
+
+	NNCPBundlePrefix = "NNCP/"
 )
 
 var (
-- 
2.48.1